Abstract: In a turbo-generator (10) having a rotor (11) and a stator (12) concentrically surrounding the rotor (11) and separated from the rotor (11) by an air gap (14), and also having a cooling arrangement in which a main fan (33) draws in a gaseous cooling medium flowing through corresponding cooling passages in the rotor (11) and in the stator (12) and forces it through a cooler (22, 23, 24) back into the cooling passages, the cooling medium flowing through the rotor (11) in the axial direction, issuing in a heated state into the air gap (14) and being returned from the air gap (14) to the main fan (33), improved rotor cooling is achieved in that the cooling medium heated by the rotor (11) is directed radially outward from the air gap (14) through outflow passages (15) in the stator (12) and is returned to the main fan (33) outside the stator (12) via a cooling-air return (21).

Abstract: In a gas-cooled electrical machine, the conductor bars (3, 4) in the winding overhang are cooled directly by a flow element of the cooling gas flow which is passed through cooling channels (8) located within the eyes (5a, 5b) of the bar ends. To this end, the bar levels of the winding bars, which are designed as a two-level bar, are spaced apart from one another in the eye region, and thus form a radial cooling channel (8). These radial cooling channels (8) are coupled to the discharge eyes (5b) by pipe connections (10) which are connected electrically, and in terms of the flow, to round connections (20). The cooling channels (9) in the round connections (20) are connected by means of insulating tubes (31) or insulating hoses to an induction area (32) of the machine fan, which is separated from the winding overhang area (30) by a bulkhead wall (33). The invention allows the bar ends and the round connections (20) connected to them in the winding overhang to be cooled optimally, since the cooling is direct.